Hematocrit and the risk of cardiovascular disease--the Framingham study: a 34-year follow-up

D R Gagnon1, T J Zhang, F N Brand

  • 1Boston University School of Public Health, Department of Epidemiology and Biostatistics, MA 02118.

Insights

High hematocrit (HCT) levels increase the risk of cardiovascular disease (CVD) mortality and morbidity. The relationship between HCT and CVD events may be J- or U-shaped, varying by sex and age.

Area of Science:

  • Cardiovascular Medicine
  • Hematology
  • Epidemiology

Background:

  • Cardiovascular disease (CVD) remains a leading cause of mortality worldwide.
  • Hematocrit (HCT), a measure of red blood cell volume, has been investigated for its potential role in CVD risk.
  • Understanding the relationship between HCT and CVD is crucial for risk stratification and prevention strategies.

Purpose of the Study:

  • To examine the long-term association between hematocrit levels and the risk of cardiovascular disease (CVD) mortality and morbidity.
  • To investigate potential sex- and age-specific differences in the HCT-CVD relationship.

Main Methods:

  • Analysis of 34-year follow-up data from 5209 participants in the Framingham cohort.
  • Assessment of the relationship between hematocrit (HCT) levels and all-cause death, CVD morbidity, and CVD mortality.
  • Stratification of analyses by sex and age groups.

Main Results:

  • Higher HCT levels (highest quintile) were associated with an increased risk of all-cause death and CVD morbidity/mortality.
  • A J- or U-shaped relationship between HCT and CVD events was observed, with increased risk at both high and low HCT values in women.
  • HCT showed significant associations with various CVD events (CHD, MI, stroke) in younger men and women, with specific associations noted in elderly women.

Conclusions:

  • Hematocrit (HCT) is a significant risk factor for certain cardiovascular disease (CVD) events.
  • The impact of HCT on CVD risk differs between sexes and age groups, suggesting a complex, non-linear association.
  • Further research is warranted to elucidate the mechanisms underlying the HCT-CVD relationship.

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